Camera Calibration Robust to Defocus Using Phase-Shifting Patterns
Camera parameters can’t be estimated accurately using traditional calibration methods if the camera is substantially defocused. To tackle this problem, an improved approach based on three phase-shifting circular grating (PCG) arrays is proposed in this paper. Rather than encoding the feature points...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2017-10-01
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| Series: | Sensors |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1424-8220/17/10/2361 |
| _version_ | 1811307461442797568 |
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| author | Bolin Cai Yuwei Wang Keyi Wang Mengchao Ma Xiangcheng Chen |
| author_facet | Bolin Cai Yuwei Wang Keyi Wang Mengchao Ma Xiangcheng Chen |
| author_sort | Bolin Cai |
| collection | DOAJ |
| description | Camera parameters can’t be estimated accurately using traditional calibration methods if the camera is substantially defocused. To tackle this problem, an improved approach based on three phase-shifting circular grating (PCG) arrays is proposed in this paper. Rather than encoding the feature points into the intensity, the proposed method encodes the feature points into the phase distribution, which can be recovered precisely using phase-shifting methods. The PCG centers are extracted as feature points, which can be located accurately even if the images are severely blurred. Unlike the previous method which just uses a single circle, the proposed method uses a concentric circle to estimate the PCG center, such that the center can be located precisely. This paper also presents a sorting algorithm for the detected feature points automatically. Experiments with both synthetic and real images were carried out to validate the performance of the method. And the results show that the superiority of PCG arrays compared with the concentric circle array even under severe defocus. |
| first_indexed | 2024-04-13T09:04:48Z |
| format | Article |
| id | doaj.art-b23deb8fb1ae42cc88002eca21abaabc |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-13T09:04:48Z |
| publishDate | 2017-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-b23deb8fb1ae42cc88002eca21abaabc2022-12-22T02:53:01ZengMDPI AGSensors1424-82202017-10-011710236110.3390/s17102361s17102361Camera Calibration Robust to Defocus Using Phase-Shifting PatternsBolin Cai0Yuwei Wang1Keyi Wang2Mengchao Ma3Xiangcheng Chen4Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, ChinaDepartment of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, ChinaDepartment of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, ChinaDepartment of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei 230088, ChinaSchool of Automation, Wuhan University of Technology, Wuhan 430070, ChinaCamera parameters can’t be estimated accurately using traditional calibration methods if the camera is substantially defocused. To tackle this problem, an improved approach based on three phase-shifting circular grating (PCG) arrays is proposed in this paper. Rather than encoding the feature points into the intensity, the proposed method encodes the feature points into the phase distribution, which can be recovered precisely using phase-shifting methods. The PCG centers are extracted as feature points, which can be located accurately even if the images are severely blurred. Unlike the previous method which just uses a single circle, the proposed method uses a concentric circle to estimate the PCG center, such that the center can be located precisely. This paper also presents a sorting algorithm for the detected feature points automatically. Experiments with both synthetic and real images were carried out to validate the performance of the method. And the results show that the superiority of PCG arrays compared with the concentric circle array even under severe defocus.https://www.mdpi.com/1424-8220/17/10/2361defocuscamera calibrationphase-shiftingfeature pointsconcentric circle |
| spellingShingle | Bolin Cai Yuwei Wang Keyi Wang Mengchao Ma Xiangcheng Chen Camera Calibration Robust to Defocus Using Phase-Shifting Patterns Sensors defocus camera calibration phase-shifting feature points concentric circle |
| title | Camera Calibration Robust to Defocus Using Phase-Shifting Patterns |
| title_full | Camera Calibration Robust to Defocus Using Phase-Shifting Patterns |
| title_fullStr | Camera Calibration Robust to Defocus Using Phase-Shifting Patterns |
| title_full_unstemmed | Camera Calibration Robust to Defocus Using Phase-Shifting Patterns |
| title_short | Camera Calibration Robust to Defocus Using Phase-Shifting Patterns |
| title_sort | camera calibration robust to defocus using phase shifting patterns |
| topic | defocus camera calibration phase-shifting feature points concentric circle |
| url | https://www.mdpi.com/1424-8220/17/10/2361 |
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